Open source · Free · Windows & Linux

Underworld Revisited

Ultima Underworld: The Stygian Abyss (1992), reimplemented in Unity and read straight from your own copy. Play it from character creation to the end, exactly as it was, or with a modern face.

Download 0.16.2 Take a look

Needs Ultima Underworld 1+2 from GOG.com. No game data included.

0dungeon levels, played through to the end
0render modes, from palette-true to URP
0ways to hear the music: AdLib, GM, MT-32, recordings
0control schemes, swapped with Shift+F2

Two lights, one dungeon

Palette or Remastered

Drag across the picture. Palette computes light like the original, through its own shade and light tables. Remastered lights the same spot with Unity's URP: relief, glow, shadows and torch light, each switchable on its own.

Remastered mode at the doors of the Abyss
Palette mode at the doors of the Abyss
Palette Remastered

Try it yourself

The graphics lab

One room on level 2, three render modes, three steps of effects. Pick a combination, and press and hold the picture to see the same mode without effects.

Palette mode, effects Full Palette · Full Hold to compare with Off

Remastered

The colour of the light

Remastered lights the dungeon with URP. Its light burns warm like a torch. Too yellow for your taste? Turn it a little cooler, or all the way to neutral white.

Remastered, warm light

Built against the original

Everything the Abyss had. And then some.

The rules are read from the original's code and checked step by step against the game. Save games go both ways between Underworld Revisited and the 1992 original.

The whole game

Nine levels with their doors, locks, traps and triggers. Combat with the original's tables, magic with runes, creatures with their goals and group alarm, and conversations running the original bytecode, trading included.

Saves both ways

Reads and writes the original's SAVE1 to SAVE4. Carry a game into DOSBox and back.

Palette effects

Ambient occlusion, grime, wall depth, glowing lava. Every pixel still a colour of the original's palette.

Music, four ways

AdLib through an OPL2 emulation, General MIDI, a Roland MT-32 emulated by Munt, or recordings you supply.

Gamepad

In both schemes, with a pointer on the stick, glyphs for Xbox, PlayStation, Nintendo and Steam Deck, every button rebindable.

Hard pixels, sharp frame

The world at the original's 320x200 resolution or up to 4x, while the interface stays crisp.

Original bugs fixed

Optional fixes for bugs of 1992 that could cost you the game. Off, and it plays exactly as it did.

English & German

Switch the interface language at once. The game's own texts can be translated by language files.

Your own rules

An optional rules.json changes combat, magic, creatures, motion and trade. Without it, the original's numbers.

Help window

Beside the view: stats with the hidden values, a live map, your notes, spells, mantras and the game's manual.

Three ways to move

Original runs the original's motion code call by call, Smooth computes the same rules frame-rate independent, and Modern is an own character motor that slides along walls and keeps the view where you look, with the original's jumps, ledges and falls.

Windows & Linux

Windows 10 or newer, and a Linux build in every release since 0.3.0. The package brings its own runtime.

Cutscenes with speech

The intro, the dreams and the end sequence, played from the original's own cutscene files.

Pointer steering or WASD

Pick your interface

One spot in the dungeon, four faces. The game switches between them from its menu while you play: the original's frame at 4:3, the frame widened, its pieces set free, or a modern scheme with free mouse look. A layout editor moves and sizes every part.

Classic 4:3: the original interface as it was in 1992.

Press Tab

Help at hand

A help window opens beside the view while you play: your stats with the hidden values, a live map with your notes, every spell and mantra, the game's own manual, and the keys of the scheme you play with.

Stats: attributes and skills, and on request the values the original keeps hidden.

Make it yours

Options for every taste

Every addition can be switched off, so the game plays as it did in 1992. And some go where few remakes go: the whole game can pull apart the colours a colour vision deficiency cannot tell apart.

A goblin with a club, scratching his head
Colours: for red, green or blue weakness the whole game pulls apart the colours that are hard to tell apart, with strength, brightness and contrast, and the health flask can be hatched while poisoned, since red and green are the very pair a red-green deficiency cannot tell apart.

Colour vision

The whole game, recoloured

The same spot with each filter: the view, the frame, the character and the flasks all follow. And when a poison turns the health flask green, it can carry a hatch as well.

Off: the colours as the original shows them.

Under the hood

Look behind the walls

A handful of debug keys show what the game keeps hidden: the tile under your feet, the object under the crosshair, the traps and triggers where they lie, the game's own variables. They are off by default; "Debug keys on" at the end of the keyboard tab under Controls switches them on.

ShiftF1
The debug display. The tile you stand on, the texture and object under the crosshair, the nearest creature, the game variables and the trap log.
N
Noclip. A free camera through walls in full bright; Page Down and Page Up change the level, N again puts the character where the camera is.
F11
Full bright, with every trap and trigger labelled where it lies.
ShiftF7
Jump to any level and tile.
ShiftF10
The spell list: search any spell and cast it, without circle, mana or check.
ShiftF11
Make a creature cast its spell at once.
Shift+F1: the debug display with an outcast in view: where you stand, its every field from goal to hearing, and what the crosshair rests on.

Preview since 0.13.0

Britannia is next

Ultima Underworld II can already be tried: its menus, character creation and saves, Britannia with its game screen, map and conversations, and its creatures. Not yet the whole of its rules, but growing with every step.

Read the UW2 plan
The throne room in the modern scheme A conversation with Nell
Lord British's throne room, in the original's game screen

Since October 2026

The journey so far

A release every few days. The full list is in the changelog.

  1. First light

    The whole game playable, from character creation to the end sequence.

  2. Modern scheme

    Free mouse look, WASD, bags, an action bar.

  3. Linux

    The first Linux build, and motion on the original's own code.

  4. Palette effects

    Depth and light, every pixel in the original's palette.

  5. Gamepad

    Every window by stick, glyphs for every pad.

  6. Music devices

    General MIDI and the Roland MT-32.

  7. Interface presets

    Classic Modular, Classic Wide, the view-angle slider.

  8. Languages

    German interface and a translation kit.

  9. Modern movement

    An own character motor, true to the original's jumps and falls.

  10. A first look at UW2

    Ultima Underworld II as a preview.

  11. Original bugs

    Optional fixes for bugs of 1992 that could end the game.

  12. Light and language

    Ambient light and a light colour for Remastered, and translations that follow French and Italian articles.

  13. Bags and frames

    The Classic preset at 4:3 in the modern scheme, bags in bags that keep their things, and the colour help across the whole screen.

Three steps

Descend

1

Get the original

Install Ultima Underworld 1+2 from GOG.com. Only this version is supported.

2

Download

Grab the latest release for Windows (10+, 64-bit) or Linux (x86-64) and unpack it into a folder of its own.

3

Play

Start UR.exe or UR.x86_64. It finds your GOG installation, or asks once for the folder with game.gog.

Download 0.16.2

Nothing is written to your installation. Save games stay compatible with the original.

How this was made

"I have been a fan of Ultima Underworld ever since it came out in 1992. In 2012 I came across uw-formats.txt and thought: why not give it a try? In 2026, with the help of Claude, I picked it up again."

The code is written by Claude (Anthropic's AI model, via Claude Code). PQMarine decides what to build, tests every behaviour against the original game and confirms or rejects the results.

Standing on the shoulders of

  • hankmorgan for the UW.EXE disassembly, UnderworldGodot and UnderworldExporter
  • abedegno for Underworld Exhumed, the byte-exact decompilation the rules are checked against
  • Pieces of 8-bit for the remake of the music
  • The authors of uw-formats.txt, where it all started